summaryrefslogtreecommitdiff
path: root/drivers/crypto/geode-aes.c
blob: fa5a9f207bc90afb94a26b101e8b018e3f3eb0aa (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
// SPDX-License-Identifier: GPL-2.0-or-later
 /* Copyright (C) 2004-2006, Advanced Micro Devices, Inc.
  */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/crypto.h>
#include <linux/spinlock.h>
#include <crypto/algapi.h>
#include <crypto/aes.h>
#include <crypto/internal/cipher.h>
#include <crypto/internal/skcipher.h>

#include <linux/io.h>
#include <linux/delay.h>

#include "geode-aes.h"

/* Static structures */

static void __iomem *_iobase;
static DEFINE_SPINLOCK(lock);

/* Write a 128 bit field (either a writable key or IV) */
static inline void
_writefield(u32 offset, const void *value)
{
	int i;

	for (i = 0; i < 4; i++)
		iowrite32(((const u32 *) value)[i], _iobase + offset + (i * 4));
}

/* Read a 128 bit field (either a writable key or IV) */
static inline void
_readfield(u32 offset, void *value)
{
	int i;

	for (i = 0; i < 4; i++)
		((u32 *) value)[i] = ioread32(_iobase + offset + (i * 4));
}

static int
do_crypt(const void *src, void *dst, u32 len, u32 flags)
{
	u32 status;
	u32 counter = AES_OP_TIMEOUT;

	iowrite32(virt_to_phys((void *)src), _iobase + AES_SOURCEA_REG);
	iowrite32(virt_to_phys(dst), _iobase + AES_DSTA_REG);
	iowrite32(len,  _iobase + AES_LENA_REG);

	/* Start the operation */
	iowrite32(AES_CTRL_START | flags, _iobase + AES_CTRLA_REG);

	do {
		status = ioread32(_iobase + AES_INTR_REG);
		cpu_relax();
	} while (!(status & AES_INTRA_PENDING) && --counter);

	/* Clear the event */
	iowrite32((status & 0xFF) | AES_INTRA_PENDING, _iobase + AES_INTR_REG);
	return counter ? 0 : 1;
}

static void
geode_aes_crypt(const struct geode_aes_tfm_ctx *tctx, const void *src,
		void *dst, u32 len, u8 *iv, int mode, int dir)
{
	u32 flags = 0;
	unsigned long iflags;
	int ret;

	/* If the source and destination is the same, then
	 * we need to turn on the coherent flags, otherwise
	 * we don't need to worry
	 */

	flags |= (AES_CTRL_DCA | AES_CTRL_SCA);

	if (dir == AES_DIR_ENCRYPT)
		flags |= AES_CTRL_ENCRYPT;

	/* Start the critical section */

	spin_lock_irqsave(&lock, iflags);

	if (mode == AES_MODE_CBC) {
		flags |= AES_CTRL_CBC;
		_writefield(AES_WRITEIV0_REG, iv);
	}

	flags |= AES_CTRL_WRKEY;
	_writefield(AES_WRITEKEY0_REG, tctx->key);

	ret = do_crypt(src, dst, len, flags);
	BUG_ON(ret);

	if (mode == AES_MODE_CBC)
		_readfield(AES_WRITEIV0_REG, iv);

	spin_unlock_irqrestore(&lock, iflags);
}

/* CRYPTO-API Functions */

static int geode_setkey_cip(struct crypto_tfm *tfm, const u8 *key,
		unsigned int len)
{
	struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);

	tctx->keylen = len;

	if (len == AES_KEYSIZE_128) {
		memcpy(tctx->key, key, len);
		return 0;
	}

	if (len != AES_KEYSIZE_192 && len != AES_KEYSIZE_256)
		/* not supported at all */
		return -EINVAL;

	/*
	 * The requested key size is not supported by HW, do a fallback
	 */
	tctx->fallback.cip->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
	tctx->fallback.cip->base.crt_flags |=
		(tfm->crt_flags & CRYPTO_TFM_REQ_MASK);

	return crypto_cipher_setkey(tctx->fallback.cip, key, len);
}

static int geode_setkey_skcipher(struct crypto_skcipher *tfm, const u8 *key,
				 unsigned int len)
{
	struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);

	tctx->keylen = len;

	if (len == AES_KEYSIZE_128) {
		memcpy(tctx->key, key, len);
		return 0;
	}

	if (len != AES_KEYSIZE_192 && len != AES_KEYSIZE_256)
		/* not supported at all */
		return -EINVAL;

	/*
	 * The requested key size is not supported by HW, do a fallback
	 */
	crypto_skcipher_clear_flags(tctx->fallback.skcipher,
				    CRYPTO_TFM_REQ_MASK);
	crypto_skcipher_set_flags(tctx->fallback.skcipher,
				  crypto_skcipher_get_flags(tfm) &
				  CRYPTO_TFM_REQ_MASK);
	return crypto_skcipher_setkey(tctx->fallback.skcipher, key, len);
}

static void
geode_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
{
	const struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);

	if (unlikely(tctx->keylen != AES_KEYSIZE_128)) {
		crypto_cipher_encrypt_one(tctx->fallback.cip, out, in);
		return;
	}

	geode_aes_crypt(tctx, in, out, AES_BLOCK_SIZE, NULL,
			AES_MODE_ECB, AES_DIR_ENCRYPT);
}


static void
geode_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
{
	const struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);

	if (unlikely(tctx->keylen != AES_KEYSIZE_128)) {
		crypto_cipher_decrypt_one(tctx->fallback.cip, out, in);
		return;
	}

	geode_aes_crypt(tctx, in, out, AES_BLOCK_SIZE, NULL,
			AES_MODE_ECB, AES_DIR_DECRYPT);
}

static int fallback_init_cip(struct crypto_tfm *tfm)
{
	const char *name = crypto_tfm_alg_name(tfm);
	struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);

	tctx->fallback.cip = crypto_alloc_cipher(name, 0,
						 CRYPTO_ALG_NEED_FALLBACK);

	if (IS_ERR(tctx->fallback.cip)) {
		printk(KERN_ERR "Error allocating fallback algo %s\n", name);
		return PTR_ERR(tctx->fallback.cip);
	}

	return 0;
}

static void fallback_exit_cip(struct crypto_tfm *tfm)
{
	struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);

	crypto_free_cipher(tctx->fallback.cip);
}

static struct crypto_alg geode_alg = {
	.cra_name			=	"aes",
	.cra_driver_name	=	"geode-aes",
	.cra_priority		=	300,
	.cra_alignmask		=	15,
	.cra_flags			=	CRYPTO_ALG_TYPE_CIPHER |
							CRYPTO_ALG_NEED_FALLBACK,
	.cra_init			=	fallback_init_cip,
	.cra_exit			=	fallback_exit_cip,
	.cra_blocksize		=	AES_BLOCK_SIZE,
	.cra_ctxsize		=	sizeof(struct geode_aes_tfm_ctx),
	.cra_module			=	THIS_MODULE,
	.cra_u				=	{
		.cipher	=	{
			.cia_min_keysize	=	AES_MIN_KEY_SIZE,
			.cia_max_keysize	=	AES_MAX_KEY_SIZE,
			.cia_setkey			=	geode_setkey_cip,
			.cia_encrypt		=	geode_encrypt,
			.cia_decrypt		=	geode_decrypt
		}
	}
};

static int geode_init_skcipher(struct crypto_skcipher *tfm)
{
	const char *name = crypto_tfm_alg_name(&tfm->base);
	struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);

	tctx->fallback.skcipher =
		crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK |
				      CRYPTO_ALG_ASYNC);
	if (IS_ERR(tctx->fallback.skcipher)) {
		printk(KERN_ERR "Error allocating fallback algo %s\n", name);
		return PTR_ERR(tctx->fallback.skcipher);
	}

	crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
				    crypto_skcipher_reqsize(tctx->fallback.skcipher));
	return 0;
}

static void geode_exit_skcipher(struct crypto_skcipher *tfm)
{
	struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);

	crypto_free_skcipher(tctx->fallback.skcipher);
}

static int geode_skcipher_crypt(struct skcipher_request *req, int mode, int dir)
{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	const struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
	struct skcipher_walk walk;
	unsigned int nbytes;
	int err;

	if (unlikely(tctx->keylen != AES_KEYSIZE_128)) {
		struct skcipher_request *subreq = skcipher_request_ctx(req);

		*subreq = *req;
		skcipher_request_set_tfm(subreq, tctx->fallback.skcipher);
		if (dir == AES_DIR_DECRYPT)
			return crypto_skcipher_decrypt(subreq);
		else
			return crypto_skcipher_encrypt(subreq);
	}

	err = skcipher_walk_virt(&walk, req, false);

	while ((nbytes = walk.nbytes) != 0) {
		geode_aes_crypt(tctx, walk.src.virt.addr, walk.dst.virt.addr,
				round_down(nbytes, AES_BLOCK_SIZE),
				walk.iv, mode, dir);
		err = skcipher_walk_done(&walk, nbytes % AES_BLOCK_SIZE);
	}

	return err;
}

static int geode_cbc_encrypt(struct skcipher_request *req)
{
	return geode_skcipher_crypt(req, AES_MODE_CBC, AES_DIR_ENCRYPT);
}

static int geode_cbc_decrypt(struct skcipher_request *req)
{
	return geode_skcipher_crypt(req, AES_MODE_CBC, AES_DIR_DECRYPT);
}

static int geode_ecb_encrypt(struct skcipher_request *req)
{
	return geode_skcipher_crypt(req, AES_MODE_ECB, AES_DIR_ENCRYPT);
}

static int geode_ecb_decrypt(struct skcipher_request *req)
{
	return geode_skcipher_crypt(req, AES_MODE_ECB, AES_DIR_DECRYPT);
}

static struct skcipher_alg geode_skcipher_algs[] = {
	{
		.base.cra_name		= "cbc(aes)",
		.base.cra_driver_name	= "cbc-aes-geode",
		.base.cra_priority	= 400,
		.base.cra_flags		= CRYPTO_ALG_KERN_DRIVER_ONLY |
					  CRYPTO_ALG_NEED_FALLBACK,
		.base.cra_blocksize	= AES_BLOCK_SIZE,
		.base.cra_ctxsize	= sizeof(struct geode_aes_tfm_ctx),
		.base.cra_alignmask	= 15,
		.base.cra_module	= THIS_MODULE,
		.init			= geode_init_skcipher,
		.exit			= geode_exit_skcipher,
		.setkey			= geode_setkey_skcipher,
		.encrypt		= geode_cbc_encrypt,
		.decrypt		= geode_cbc_decrypt,
		.min_keysize		= AES_MIN_KEY_SIZE,
		.max_keysize		= AES_MAX_KEY_SIZE,
		.ivsize			= AES_BLOCK_SIZE,
	}, {
		.base.cra_name		= "ecb(aes)",
		.base.cra_driver_name	= "ecb-aes-geode",
		.base.cra_priority	= 400,
		.base.cra_flags		= CRYPTO_ALG_KERN_DRIVER_ONLY |
					  CRYPTO_ALG_NEED_FALLBACK,
		.base.cra_blocksize	= AES_BLOCK_SIZE,
		.base.cra_ctxsize	= sizeof(struct geode_aes_tfm_ctx),
		.base.cra_alignmask	= 15,
		.base.cra_module	= THIS_MODULE,
		.init			= geode_init_skcipher,
		.exit			= geode_exit_skcipher,
		.setkey			= geode_setkey_skcipher,
		.encrypt		= geode_ecb_encrypt,
		.decrypt		= geode_ecb_decrypt,
		.min_keysize		= AES_MIN_KEY_SIZE,
		.max_keysize		= AES_MAX_KEY_SIZE,
	},
};

static void geode_aes_remove(struct pci_dev *dev)
{
	crypto_unregister_alg(&geode_alg);
	crypto_unregister_skciphers(geode_skcipher_algs,
				    ARRAY_SIZE(geode_skcipher_algs));

	pci_iounmap(dev, _iobase);
	_iobase = NULL;

	pci_release_regions(dev);
	pci_disable_device(dev);
}


static int geode_aes_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
	int ret;

	ret = pci_enable_device(dev);
	if (ret)
		return ret;

	ret = pci_request_regions(dev, "geode-aes");
	if (ret)
		goto eenable;

	_iobase = pci_iomap(dev, 0, 0);

	if (_iobase == NULL) {
		ret = -ENOMEM;
		goto erequest;
	}

	/* Clear any pending activity */
	iowrite32(AES_INTR_PENDING | AES_INTR_MASK, _iobase + AES_INTR_REG);

	ret = crypto_register_alg(&geode_alg);
	if (ret)
		goto eiomap;

	ret = crypto_register_skciphers(geode_skcipher_algs,
					ARRAY_SIZE(geode_skcipher_algs));
	if (ret)
		goto ealg;

	dev_notice(&dev->dev, "GEODE AES engine enabled.\n");
	return 0;

 ealg:
	crypto_unregister_alg(&geode_alg);

 eiomap:
	pci_iounmap(dev, _iobase);

 erequest:
	pci_release_regions(dev);

 eenable:
	pci_disable_device(dev);

	dev_err(&dev->dev, "GEODE AES initialization failed.\n");
	return ret;
}

static struct pci_device_id geode_aes_tbl[] = {
	{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_LX_AES), },
	{ 0, }
};

MODULE_DEVICE_TABLE(pci, geode_aes_tbl);

static struct pci_driver geode_aes_driver = {
	.name = "Geode LX AES",
	.id_table = geode_aes_tbl,
	.probe = geode_aes_probe,
	.remove = geode_aes_remove,
};

module_pci_driver(geode_aes_driver);

MODULE_AUTHOR("Advanced Micro Devices, Inc.");
MODULE_DESCRIPTION("Geode LX Hardware AES driver");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS(CRYPTO_INTERNAL);